In a cassette library device of this type, as illustrated in FIG. 15, a plurality of garages 4 are annularly mounted on a turn table 2, and a cassette 1 is stored in each garage 4. Then, a drive mechanism 3 rotates the turn table 2 such that a garage 4 having a target cassette 1 stored therein faces an elevator mechanism 5. The elevator mechanism 5 takes out the target cassette 1 from the garage 4, and inserts/removes the cassette 1 into/from a tape drive 6; thus, information is read from/written to the cassette 1 (Non-Patent Document 1).
With this configuration, a cassette can be automatically inserted into/removed from the tape drive 6 within a range of a data library contained in the turn table 2. However, in order to increase, in number, cassettes 1 to be stored as a data library in a limited space, a magazine-type cassette library device illustrated in FIG. 16 is suitable as compared with the aforementioned turn table-type cassette library device.
The magazine-type cassette library device has a configuration that a tape drive 6 and a pair of magazine-type garages 8a and 8b are mounted in a casing 7.
A plurality of cassettes 1 arranged in a line are stored in each of the garages 8a and 8b. A picker 9 interposed between the pair of garages 8a and 8b transfers a cassette 1 between the garage 8a (8b) and the tape drive 6.
FIGS. 17(a), 17(b), 17(c) and 18 illustrate one example of a cassette 1.
The cassette 1 is formed into a thin, rectangular parallelepiped shape as illustrated in FIGS. 17(a) to 17(c). Recesses 10a and 10b are formed at both ends on a bottom side of the cassette 1. The cassette 1 includes a bottom face 11 and side faces 12a and 12b. 
As illustrated in FIG. 16, a cassette 1 is stored in one of the garages 8a and 8b such that recesses 10a and 10b thereof are located at an open side of the garage 8a (8b), that is, the recesses 10a and 10b are located near the picker 9.
As illustrated in FIGS. 16 and 19, the picker 9 includes a movable unit 15 capable of moving in a horizontal direction. As illustrated in FIGS. 16 to 19, the movable unit 15 has a pair of rocking arms 16a and 16b each capable of rocking in a vertical direction. As illustrated in FIG. 18, each of the rocking arms 16a and 16b includes a main body 17 extending in the horizontal direction and a tip end 18 bent upward at one end of the main body 17.
When the rocking arms 16a and 16b rock upward in a state that the movable unit 15 of the picker 9 approaches the cassette 1 stored in the garage 8a (8b) as illustrated in FIG. 19, the main bodies 17 come into contact with the bottom face 11 of the cassette 1 and the tip ends 18 are fitted into the recesses 10a and 10b. Thus, the rocking arms 16a and 16b chuck the cassette 1.
In this state, the movable body 15 moves so as to be away from the garages 8a and 8b, so that the cassette 1 can be taken out from the garage 8a (8b).
As illustrated in FIGS. 16 and 19, the movable unit 15 has guide rails 19, and the cassette 1 taken out from the garage 8a (8b) is placed on the guide rails 19. Thus, transfer of the cassette 1 from one of the garages 8a and 8b to the picker 9 is completed.
Non-Patent Document 1: “2002 New Technology of Matsushita Electric”, May 2003, pp. 155-159, (DDS-Equipped Backup Library), issued by R&D Planning Office of Matsushita Electric Industrial